کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1262414 971863 2007 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Crystallization Kinetics of Misch Metal Based Bulk Metallic Glasses
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Crystallization Kinetics of Misch Metal Based Bulk Metallic Glasses
چکیده انگلیسی

The crystallization kinetics of Mm55Al25Cu10Ni5Co5 bulk metallic glass (BMG) was investigated by means of differential scanning calorimetry (DSC) in the mode of continuous heating or isothermal annealing. It was found that the apparent activation energy Eg, Ex and Ep of the BMG calculated by Kissinger's method were 189.58, 170.68 and 170.41 kJ·mol−1, respectively, which was bigger than those of La55Al25Cu10Ni5Co5 BMG indicating that thermal stability of the former was higher than that of the latter. The local activation energy obtained using Ozawa equation decreased as crystallization proceeded except for the initial stage. The Avrami exponents were calculated to be in the range of 3.26 ∼ 5.23 for different crystallization stages and isothermal temperatures. This implied that crystallization of Mm55 Al25Cu10Ni5Co5 BMG was governed by diffusion-controlled three-dimensional growth with either reduced or increased nucleation rate, depending on isothermal temperature. Inconsistency of thermal stability with glass-forming ability for Mm(La)-Al-Cu-Ni-Co BMGs was discussed.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Rare Earths - Volume 25, Issue 2, April 2007, Pages 189-193